530hp...perhaps. 800 torque...no. At the flywheel, my mildly modded LS6 (347cid) makes right at 500hp and 500 torque.
Crate engine versions of the LS3 currently available.
LS3 stock: 430 HP @ 5900 RPM, 424 ft. lbs. of torque @ 4600 RPM
LS376/480: 480 HP @ 5750 RPM, 475 ft. lbs. of torque @ 4500 RPM
LS376/525: 525 horsepower at 6,300 rpm and 489 lb.-ft. at 4,400 rpm